Phyllis Hildreth has an understanding with her father about the machine he gave her after he retired from the watchmaking business. It is for her eyes only. No one else is allowed to catch even a glimpse. When she is not using the machine, it remains covered with a blue towel.

The machine -- designed and built 20 years ago by Hildreth's father, Harvey Watkins -- is used to refinish tweezers. And not just any tweezers, but the stainless-steel, $10-to-$15-a-pair variety used by watchmakers and electronics assemblers.

Watkins didn't take out a patent on his machine because he thought few folks would need, or could afford it. Still, he wants to guard against even the remote possibility of his invention being copied. Before retiring two years ago, he taught his daughter to use the machine -- and to cover it up if someone else was in the room.

She now operates a business, Watkins Tweezer Refinishing, from her Mount Dora home. She uses a machine built by her father. It's modeled on the original, which he keeps under wraps in his home in Plant City.